Preliminary Design of Long‐Span King‐Post Truss Systems with a Genetic Algorithm

2001 ◽  
Vol 16 (2) ◽  
pp. 94-105 ◽  
Author(s):  
Lei Xu ◽  
Yanglin Gong
Keyword(s):  
Genetic Algorithm ◽  
Preliminary Design ◽  
Long Span

Seismic Performance of the Buckling-Restrained Brace Central Buckle for Long-Span Suspension Bridges

2018 ◽  
Vol 12 (05) ◽  
pp. 1850015 ◽  
Author(s):  
Wei Guo ◽  
Jianzhong Li ◽  
Nailiang Xiang
Keyword(s):  
Seismic Performance ◽  
Design Procedure ◽  
Suspension Bridges ◽  
Preliminary Design ◽  
Viscous Dampers ◽  
Buckling Restrained Brace ◽  
Long Span ◽  
Parametric Analyses ◽  
Yield Force ◽  
Central Buckle

In this paper, a novel central buckle composed of buckling-restrained braces (BRBs) is developed for long-span suspension bridges, and its preliminary design procedure is presented. Seismic performance of suspension bridges equipped with BRB central buckles is investigated and compared with those with conventional central buckles (e.g. rigid or flexible central buckles). Furthermore, the effect of BRB yield force, as well as the effectiveness of BRB central buckles combined with viscous dampers, is evaluated using parametric analyses. The results indicate that the BRB central buckle is more effective than other central buckles in reducing both the longitudinal girder displacements and force demands on towers during an earthquake. Furthermore, the combination of BRB central buckles and viscous dampers is a superior option for mitigating the seismic response of long-span suspension bridges.

Using Genetic Algorithms to Set Target Values for Engineering Characteristics in the House of Quality

1999 ◽  
Author(s):  
Patricia Brackin ◽  
Jonathan Colton
Keyword(s):  
Genetic Algorithm ◽  
Genetic Algorithms ◽  
Penalty Functions ◽  
Preliminary Design ◽  
Test Results ◽  
House Of Quality ◽  
Design Specifications ◽  
Engineering Characteristics ◽  
Target Values

Abstract As part of a strategy for obtaining preliminary design specifications from the House of Quality, genetic algorithms were used to generate and optimize preliminary design specifications for an automotive case study. This paper describes the House of Quality for the automotive case study. In addition, the genetic algorithm chosen, the genetic coding, the methods used for mutation and reproduction, and the fitness and penalty functions are descrobed. Methods for determining convergence are examined. Finally, test results show that the genetic algorithm produces reasonable preliminary design specifications.

Rapid Preliminary Design of Floating Offshore Structures Using a Modified Genetic Algorithm

2007 ◽  
Author(s):  
Michael J. Perry ◽  
John E. Halkyard ◽  
C. G. Koh
Keyword(s):  
Genetic Algorithm ◽  
Cost Effective ◽  
Offshore Structures ◽  
Preliminary Design ◽  
Optimization Strategy ◽  
Empirical Estimates ◽  
Wind Speed Maximum ◽  
Design Wind Speed ◽  
Truss Spar ◽  
Weight Design

Preliminary design of floating offshore structures involves determining structural dimensions able to provide sufficient buoyancy to carry the required topside, at the lowest possible cost, while satisfying various stability, strength, installation, and response requirements. A novel optimization strategy, capable of carrying out the preliminary design of floating offshore structures, is presented in this paper. The genetic algorithm based strategy searches within prescribed parameter limits for the most cost effective design, while ensuring the design conforms to the constraints given. The design of a truss spar is used to illustrate how the strategy can be applied. The topside weight, design wind speed, maximum wave height, etc are input along with constraints such as, maximum draft at floatoff, maximum heel angle, allowable stress in the truss and limits on pitch and heave period and response. Using empirical estimates for hull weights and simplified response calculations, the strategy is then able to rapidly determine parameters such as hull diameter, hard tank depth, length of keel tank, total length and truss leg diameter such that the total cost of the structure is minimized. The strategy allows for the preliminary design phase to be completed in only a few seconds, while providing initial weight and cost estimates.

Optimization of Multi-Modal Discrete Functions Using Genetic Algorithms

1993 ◽  
Vol 207 (1) ◽  
pp. 53-59 ◽  
Author(s):  
D T Pham ◽  
Y Yang
Keyword(s):  
Genetic Algorithm ◽  
Genetic Algorithms ◽  
Optimization Problem ◽  
Approximate Solutions ◽  
Solution Set ◽  
Preliminary Design ◽  
Potential Solution ◽  
Reproduction Cycle ◽  
Fitness Sharing ◽  
Discrete Functions

Four techniques are described which can help a genetic algorithm to locate multiple approximate solutions to a multi-modal optimization problem. These techniques are: fitness sharing, ‘eliminating’ identical solutions, ‘removing’ acceptable solutions from the reproduction cycle and applying heuristics to improve sub-standard solutions. Essentially, all of these techniques operate by encouraging genetic variety in the potential solution set. The preliminary design of a gearbox is presented as an example to illustrate the effectiveness of the proposed techniques.

Ramjet Powered Missile Design Using a Genetic Algorithm

2007 ◽  
Vol 7 (2) ◽  
pp. 167-173 ◽  
Author(s):  
Roy J. Hartfield ◽  
Rhonald M. Jenkins ◽  
John E. Burkhalter
Keyword(s):  
Genetic Algorithm ◽  
Performance Prediction ◽  
Design Space ◽  
System Optimization ◽  
Design Strategy ◽  
Optimization Process ◽  
Preliminary Design ◽  
Efficient Exploration ◽  
Typical Design ◽  
Design Scenario

A methodology for developing optimized designs for symmetric-centerbody ramjet powered missiles, using a genetic algorithm as the driver for the system optimization process, has been developed. The methodology described in this paper allows for a comprehensive but efficient exploration of the design space. This global optimization process is made possible by performance prediction codes, which can provide preliminary design-level accuracy very efficiently. This work demonstrates the first truly comprehensive design strategy for this type of device. The paper contains a discussion of the methodology and shows results for a typical design scenario.

A Genetic Algorithm Based Preliminary Design System

1993 ◽  
Vol 207 (2) ◽  
pp. 127-133 ◽  
Author(s):  
D T Pham ◽  
Y Yang
Keyword(s):  
Genetic Algorithm ◽  
Design Stage ◽  
Design System ◽  
Prototype System ◽  
Preliminary Design ◽  
Design Concepts ◽  
Computer Aided ◽  
Preliminary Design Stage

The different stages in design are briefly discussed. Examples of previous research into automating the preliminary design stage are described. An architecture for a computer aided preliminary design system is proposed. A prototype system for generating design concepts for transmission devices is presented.

Using Genetic Algorithms to Set Target Values for Engineering Characteristics in the House of Quality

2002 ◽  
Vol 2 (2) ◽  
pp. 106-114 ◽  
Author(s):  
Patricia Brackin ◽  
Jonathan S. Colton
Keyword(s):  
Genetic Algorithm ◽  
Genetic Algorithms ◽  
Penalty Functions ◽  
Preliminary Design ◽  
Test Results ◽  
House Of Quality ◽  
Design Specifications ◽  
Engineering Characteristics ◽  
Target Values

As part of a strategy for obtaining preliminary design specifications from the House of Quality, genetic algorithms are used to generate and optimize preliminary design specifications for an automotive case study. This paper describes the House of Quality for an automotive case study. In addition, the genetic algorithm chosen, the genetic coding, the methods used for mutation and reproduction, and the fitness and penalty functions are described. Methods for determining convergence are examined. Finally, test results show that the genetic algorithm produces reasonable preliminary design specifications.

Mechanics Characteristics Study for Cable-Stayed-Suspension Bridges

2011 ◽  
Vol 243-249 ◽  
pp. 1817-1825
Author(s):  
Jing Qiu ◽  
Rui Li Shen ◽  
Huai Guang Li
Keyword(s):  
Finite Element ◽  
Suspension Bridge ◽  
Simulation Method ◽  
Suspension Bridges ◽  
Preliminary Design ◽  
Structural System ◽  
Long Span Bridges ◽  
Long Span ◽  
Element Simulation ◽  
Mechanics Characteristics

As a composite structure, the cable-stayed-suspension bridge is characterized by relatively new structure, great overall stiffness and long-span capacity, which has been proposed for the design of some extra long-span bridges. In order to research further into the mechanics characteristics of this type of structural system, the proposed preliminary design of a cable-stayed-suspension bridge with a main span of 1800m is analyzed by means of finite element simulation method. The advantages on overall stiffness in the cable-stayed-suspension bridge are summarized in comparison with the three-span suspension bridge and the single-span suspension bridge. Then, the reasons for the fatigue of the longest suspension cables in the cable-stayed-suspension bridge are also discussed in this paper.

Genetic Algorithm-Based Clustering Method to Formulate Standard Specifications for Merchant Ship Preliminary Design

2021 ◽  
Author(s):  
Chenwei Gui ◽  
Ranyi Zeng ◽  
Kenji Takahashi ◽  
Naoki Herai ◽  
Kazuhiro Aoyama
Keyword(s):  
Genetic Algorithm ◽  
Main Type ◽  
Ship Design ◽  
Preliminary Design ◽  
Clustering Method ◽  
Standard Specification ◽  
Merchant Ship ◽  
Economic Constraints

Abstract In the preliminary design of merchant ships, shipbuilders generally modify some of the standard specifications to fulfill shipowner needs, which is time-consuming owing to the complex techno-economic constraints of ship design. Therefore, an appropriate standard specifications formulation method is necessary to improve the efficiency of the preliminary design. In this study, we performed genetic algorithm-based clustering to determine the subtypes of a specific type of merchant ship and formulated the standard specification for each subtype. To demonstrate the effectiveness of the proposed method, experiments were performed using 98 specification documents to formulate the standard specifications. The results showed that feature relations among each determined subtype were significantly simpler than those of the main type; thereby, the formulated standard specifications were desirable in the preliminary design of merchant ships.

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